Remove the, now unused, releaseImageResources helper function

With the changes in the previous patch, this is now dead code which should thus be removed.

src/display/api.js

@@ -43,7 +43,6 @@ import {
   DOMCMapReaderFactory,
   loadScript,
   PageViewport,
-  releaseImageResources,
   RenderingCancelledException,
   StatTimer,
 } from "./display_utils.js";
@@ -2581,14 +2580,6 @@ class PDFObjects {
   }
 
   clear() {
-    for (const objId in this._objs) {
-      const { data } = this._objs[objId];
-
-      if (typeof Image !== "undefined" && data instanceof Image) {
-        // Always release the image data when clearing out the cached objects.
-        releaseImageResources(data);
-      }
-    }
     this._objs = Object.create(null);
   }
 }

src/display/display_utils.js

@@ -517,20 +517,6 @@ function deprecated(details) {
   console.log("Deprecated API usage: " + details);
 }
 
-function releaseImageResources(img) {
-  assert(img instanceof Image, "Invalid `img` parameter.");
-
-  const url = img.src;
-  if (
-    typeof url === "string" &&
-    url.startsWith("blob:") &&
-    URL.revokeObjectURL
-  ) {
-    URL.revokeObjectURL(url);
-  }
-  img.removeAttribute("src");
-}
-
 let pdfDateStringRegex;
 
 class PDFDateString {
@@ -631,6 +617,5 @@ export {
   isValidFetchUrl,
   loadScript,
   deprecated,
-  releaseImageResources,
   PDFDateString,
 };